[annie123 (OP)]

In a lamenectomy bone is shaved off the vertebrae to make space for the nerve, so where does the waste bone go? if it's in powdery form could some get embedded in the nerve?

[alancalverd]

Laminectomy diagrams show complete removal of the spinous process and its supporting arch laminae to decompress the nerve sheath, so any cutting debris will have been removed by suction during the cutting process. 

[Bored chemist]

"where does the waste bone go? "
Clinical waste bin.